1. Field of the Invention
The present invention relates to methods and apparatuses for initializing injectors based on temporarily input correction values for the injectors.
2. Description of the Related Art
Conventional methods of initializing a fuel injection system with an injector for each cylinder of an engine are disclosed, for example, in International Unexamined Patent Publication No. WO97/20136 corresponding to National Publication of Translated Version No. 2000-501155.
Such conventional initializing methods include a step of storing beforehand in a storage medium a unique correction value previously determined for each injector such that the correction value is associated with an identifier of a corresponding one of the cylinders.
The correction values of the individual injectors are required to determine fuel-quantity parameters including optimum fuel injection timings and optimum fuel injection periods for the individual injectors; these fuel-quantity parameters are required to equalize fuel-injection quantities therefrom.
After the initialization, the fuel-injection parameters including the optimum fuel injection timings and the optimum fuel injection periods are computed based on the unique correction values of the individual injectors stored in the storage medium. Accordingly, the individual injectors are precisely controlled based on the corresponding fuel-injection parameters so that actual fuel injection quantities from the injectors are equalized to each other.
In the conventional methods of initializing a fuel injection system with an injector for each cylinder of an engine, an operator manipulates a writing device to write a unique correction value for each injector (each cylinder) into a computer-accessible storage medium so that it is stored therein. For this reason, there is the possibility that the operator manipulates the writing device to write wrong correction data for at least one injector (at least one cylinder) into the computer-accessible storage medium.
In this wrong correct-value writing case, in the at least one cylinder, the wrong correct value stored in the storage medium and a real correct value uniquely determined for the at least one injector corresponding to the at least one cylinder have a gap therebetween.
When the fuel-injection parameters are computed based on the wrong correction data of the at least one injector, the gap may therefore cause nonuniform distributions between the fuel quantities of the injectors.
It is to be noted that Japanese Unexamined Patent Publication No. 2002-180897 focuses on identification of an information storage medium in which correction values are stored in advance, which is probably different from the injection-quantity distribution problem.